Normally I have had very good experiences as well. My colleagues almost always speak very good English and even those who don't are understandable. Everyone is happy to conduct meetings (with many nationalities, as I work in a scientific field) in English.
Only once have I encountered a problem. A colleague berated me in front of others for speaking "difficult English" and accused me of doing this on purpose to cause trouble for them, instead of speaking proper international English like everyone else did. But, I am a native English speaker with an RP accent and we were all in England at the time, working for a British organisation. I was simply speaking normally and otherwise had no issue with this colleague, whose English was very good. I don't recall their having been any misunderstandings between us before.
Only once have I encountered a problem. A colleague berated me in front of others for speaking "difficult English" and accused me of doing this on purpose to cause trouble for them, instead of speaking proper international English like everyone else did. But, I am a native English speaker with an RP accent and we were all in England at the time, working for a British organisation. I was simply speaking normally and otherwise had no issue with this colleague, whose English was very good. I don't recall their having been any misunderstandings between us before.